U.S. patent application number 14/404449 was filed with the patent office on 2015-04-23 for substrate treating apparatus and method.
The applicant listed for this patent is JUSUNG ENGINEERING CO., LTD.. Invention is credited to Jeung Hoon Han, Chul Joo Hwang, Young Hoon Kim, Seung Hoon Seo.
Application Number | 20150111391 14/404449 |
Document ID | / |
Family ID | 49673587 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150111391 |
Kind Code |
A1 |
Hwang; Chul Joo ; et
al. |
April 23, 2015 |
SUBSTRATE TREATING APPARATUS AND METHOD
Abstract
Disclosed is an apparatus and method of processing substrate,
which facilitates to improve deposition uniformity of a thin film
deposited on a substrate, and to control quality of a thin film,
wherein the apparatus includes a process chamber; a substrate
supporter for supporting at least one of substrates, wherein the
substrate supporter is provided in the bottom of the process
chamber; a chamber lid confronting the substrate supporter, the
chamber lid for covering an upper side of the process chamber; and
a gas distributor for locally distributing activated source gas on
the substrate, wherein the gas distributor locally confronting the
substrate supporter is provided in the chamber lid, wherein the gas
distributor forms plasma by the use of plasma formation gas, and
activates the source gas by distributing the source gas to some of
plasma area for formation of the plasma.
Inventors: |
Hwang; Chul Joo;
(Seongnam-si, KR) ; Han; Jeung Hoon; (Gwangju-si,
KR) ; Kim; Young Hoon; (Uiwang-si-si, KR) ;
Seo; Seung Hoon; (Gwangju-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JUSUNG ENGINEERING CO., LTD. |
Gwangju-si, Gyeonggi-do |
|
KR |
|
|
Family ID: |
49673587 |
Appl. No.: |
14/404449 |
Filed: |
May 28, 2013 |
PCT Filed: |
May 28, 2013 |
PCT NO: |
PCT/KR2013/004678 |
371 Date: |
November 26, 2014 |
Current U.S.
Class: |
438/758 ;
118/723R |
Current CPC
Class: |
C23C 16/50 20130101;
C23C 16/45574 20130101; C23C 16/54 20130101; H01L 21/02532
20130101; C23C 16/4584 20130101; C23C 16/455 20130101; C23C
16/45563 20130101; H01L 21/28556 20130101; C23C 16/45551 20130101;
H01J 37/32532 20130101; H01J 37/32752 20130101; C23C 16/458
20130101; H01J 37/32082 20130101; H01J 37/3244 20130101; H01L
21/0262 20130101; C23C 16/45544 20130101; C23C 16/45536 20130101;
C23C 16/5096 20130101; H01L 21/67155 20130101; C23C 16/509
20130101; H01L 21/32051 20130101 |
Class at
Publication: |
438/758 ;
118/723.R |
International
Class: |
C23C 16/50 20060101
C23C016/50; C23C 16/458 20060101 C23C016/458; H01L 21/3205 20060101
H01L021/3205; C23C 16/455 20060101 C23C016/455; H01L 21/02 20060101
H01L021/02; H01L 21/285 20060101 H01L021/285 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2012 |
KR |
10-2012-0057047 |
Claims
1. A substrate processing apparatus comprising: a process chamber;
a substrate supporter for supporting at least one of substrates,
wherein the substrate supporter is provided in the bottom of the
process chamber; a chamber lid confronting the substrate supporter,
the chamber lid for covering an upper side of the process chamber;
and a gas distributor for locally distributing activated source gas
on the substrate, wherein the gas distributor locally confronting
the substrate supporter is provided in the chamber lid, wherein the
gas distributor forms plasma by the use of plasma formation gas,
and activates the source gas by distributing the source gas to some
of plasma area for formation of the plasma.
2. The apparatus of claim 1, wherein the gas distributor includes
first and second plasma formation spaces which are spatially
separated from each other, and are supplied with the plasma
formation gas; and a source gas distribution space which is
provided between the first and second plasma formation spaces so as
to separate the first and second plasma formation spaces from each
other, and is supplied with the source gas, wherein the source gas
is activated by plasma formed to include some of a lower area of
the source gas distribution space.
3. The apparatus of claim 2, wherein the gas distributor includes a
plurality of gas distribution modules for distributing the
activated source gas on the substrate, wherein the plurality of gas
distribution modules locally confronting different areas of the
substrate supporter are provided in the chamber lid, wherein each
of the gas distribution modules includes: a housing having a
plurality of ground electrodes formed to spatially separate the
first and second plasma formation spaces from the source gas
distribution space, wherein the housing is electrically grounded to
the chamber lid; and first and second plasma electrodes which are
respectively inserted into the first and second plasma formation
spaces so as to be electrically insulated from the housing, and are
supplied with plasma power.
4. The apparatus of claim 3, wherein a distance between the
substrate and a lower surface of each of the first and second
plasma electrodes is the same as or different from a distance
between the substrate and a lower surface of the ground
electrode.
5. The apparatus of claim 2, wherein the gas distributor includes a
plurality of gas distribution modules for distributing the
activated source gas on the substrate, wherein the plurality of gas
distribution modules locally confronting different areas of the
substrate supporter are provided in the chamber lid, wherein each
of the gas distribution modules includes: a housing having a
plurality of ground electrodes provided with a ground partition and
a plurality of ground sidewalls to spatially separate the first and
second plasma formation spaces from each other, wherein the housing
is electrically grounded to the chamber lid; and first and second
plasma electrodes which are respectively inserted into the first
and second plasma formation spaces so as to be electrically
insulated from the housing, and are supplied with plasma power,
wherein the source gas distribution space penetrates through the
ground partition for spatially separating the first and second
plasma formation spaces from each other.
6. The apparatus of claim 1, wherein the plasma formation gas is
formed of inert gas or reactant gas which reacts with the source
gas.
7. The apparatus of claim 1, wherein the source gas includes
reactant gas which reacts with the source gas.
8. The apparatus of claim 3, wherein each of the gas distribution
modules further includes a reactant gas distribution space
penetrating through the inside of each of the first and second
plasma electrodes, wherein the reactant gas distribution space is
supplied with reactant gas which reacts with the source gas,
wherein the reactant gas is activated by plasma formed to include
some of lower area of the reactant gas distribution space, and is
then distributed on the substrate.
9. A substrate processing apparatus comprising: a process chamber;
a substrate supporter for supporting at least one of substrates,
wherein the substrate supporter is provided in the bottom of the
process chamber; a chamber lid confronting the substrate supporter,
the chamber lid for covering an upper side of the process chamber;
and a gas distributor for locally distributing activated source gas
on the substrate, wherein the gas distributor locally confronting
the substrate supporter is provided in the chamber lid, and is
formed to include a plasma formation space prepared between a
plasma electrode and a ground electrode, and a source gas
distribution space spatially separated from the plasma formation
space, wherein the gas distributor distributes source gas to some
of plasma area formed to include a lower area of the source gas
distribution space through the source gas distribution space, and
thus activates the source gas.
10. A substrate processing apparatus comprising: a process chamber;
a substrate supporter for supporting at least one of substrates,
wherein the substrate supporter is provided in the bottom of the
process chamber; a chamber lid confronting the substrate supporter,
the chamber lid for covering an upper side of the process chamber;
and a gas distributor for locally distributing activated source gas
on the substrate, wherein the gas distributor locally confronting
the substrate supporter is provided in the chamber lid, wherein the
gas distributor forms plasma between plasma and ground electrodes
arranged in parallel, and distributes source gas to a plasma
overlapping area for formation of the plasma, and thus activates
the source gas.
11. A substrate processing method comprising: placing at least one
substrate on a substrate supporter provided inside a process
chamber; and locally distributing activated source gas on the
substrate by the use of gas distributor which locally confronts the
substrate supporter and is provided in a chamber lid for covering
the process chamber, wherein the gas distributor forms plasma by
the use of plasma formation gas, and distributes source gas to a
plasma overlapping area for formation of the plasma, and thus
activates the source gas.
12. The method of claim 11, wherein the gas distributor includes
first and second plasma formation spaces which are spatially
separated from each other, and are supplied with the plasma
formation gas; and a source gas distribution space which is
provided between the first and second plasma formation spaces so as
to separate the first and second plasma formation spaces from each
other, and is supplied with the source gas, wherein the source gas
is activated by plasma formed to include some of a lower area of
the source gas distribution space.
13. The method of claim 12, wherein the gas distributor includes a
plurality of ground electrodes formed to spatially separate the
first and second plasma formation space from the source gas
distribution space, and first and second plasma electrodes
respectively inserted into the first and second plasma formation
spaces, wherein the step of locally distributing the activated
source gas on the substrate includes: supplying plasma formation
gas to each of the first and second plasma formation spaces;
forming plasma to include some of a lower area of the source gas
distribution space by supplying plasma power to the first and
second plasma electrodes; and distributing the source gas to the
plasma area formed in the lower area of the source gas distribution
space through the source gas distribution space, and activating the
source gas.
14. The method of claim 12, wherein the gas distributor includes a
plurality of ground electrodes formed to spatially separate the
first and second plasma formation space from each other, first and
second plasma electrodes respectively inserted into the first and
second plasma formation spaces, and the source gas distribution
space penetrating through a ground partition for spatially
separating the first and second plasma formation spaces from each
other, wherein the step of locally distributing the activated
source gas on the substrate includes: supplying plasma formation
gas to each of the first and second plasma formation spaces;
forming plasma to include some of a lower area of the source gas
distribution space by supplying plasma power to the first and
second plasma electrodes; and distributing the source gas to the
plasma area formed in the lower area of the source gas distribution
space through the source gas distribution space, and activating the
source gas.
15. The method of claim 13, wherein a distance between the
substrate and a lower surface of each of the first and second
plasma electrodes is the same as or different from a distance
between the substrate and a lower surface of the ground
electrode.
16. The method of claim 11, wherein the plasma formation gas is
formed of inert gas or reactant gas which reacts with the source
gas.
17. The method of claim 11, wherein the source gas includes
reactant gas which reacts with the source gas.
18. The method of claim 13, further comprising distributing
reactant gas which reacts with the source gas to the plasma area
formed to include some of a lower area of reactant gas distribution
space through the reactant gas distribution space penetrating
through each of the first and second plasma electrodes, activating
the reactant gas, and distributing the activated reactant gas on
the substrate.
19. A substrate processing method comprising: placing at least one
substrate on a substrate supporter provided inside a process
chamber; and locally distributing activated source gas on the
substrate by the use of gas distributor which locally confronts the
substrate supporter and is provided in a chamber lid for covering
the process chamber, wherein the step of locally distributing the
activated source gas on the substrate includes forming plasma
between plasma and ground electrodes arranged in parallel, and
distributing source gas to a plasma overlapping area for formation
of the plasma, and thus activating the source gas.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the Korean Patent
Application No. 10-2012-0057047 filed on May 30, 2012, which is
hereby incorporated by reference as if fully set forth herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus and method of
processing substrate which deposits a thin film on a substrate.
[0004] 2. Discussion of the Related Art
[0005] Generally, in order to manufacture a solar cell, a
semiconductor device and a flat panel display device, it is
necessary to form a predetermined thin film layer, a thin film
circuit pattern or an optical pattern on a surface of a substrate.
Thus, a semiconductor manufacturing process may be carried out, for
example, a thin film deposition process of depositing a thin film
of a predetermined material on a substrate, a photo process of
selectively exposing the thin film by the use of photosensitive
material, and an etching process of forming a pattern by
selectively removing an exposed portion of the thin film.
[0006] The semiconductor manufacturing process is performed inside
a substrate processing apparatus designed to be suitable for
optimal circumstances. Recently, a substrate processing apparatus
using plasma is generally used to carry out a deposition or etching
process.
[0007] This semiconductor manufacturing process using plasma may be
a PECVD (Plasma Enhanced Chemical Vapor Deposition) apparatus for
forming a thin film, and a plasma etching apparatus for etching and
patterning the thin film.
[0008] FIG. 1 illustrates a substrate processing apparatus
according to the related art.
[0009] Referring to FIG. 1, the substrate processing apparatus
according to the related art may include a chamber 10, a plasma
electrode 20, a susceptor 30, and a gas distributing means 40.
[0010] The chamber 10 provides a reaction space for substrate
processing. In this case, a predetermined portion of a bottom
surface of the chamber 10 is communicated with an exhaust pipe 12
for discharging gas from the reaction space.
[0011] The plasma electrode 20 is provided on the chamber 10 so as
to seal the reaction space.
[0012] One side of the plasma electrode 20 is electrically
connected with a RF (Radio Frequency) power source 24 through a
matching member 22. The RF power source 24 generates RF power, and
supplies the generated RF power to the plasma electrode 20.
[0013] Also, a central portion of the plasma electrode 20 is
communicated with a gas supply pipe 26 of supplying source gas for
the substrate processing.
[0014] The matching member 22 is connected between the plasma
electrode 20 and the RF power source 24, to thereby match load
impedance and source impedance of the RF power supplied from the RF
power source 24 to the plasma electrode 20.
[0015] The susceptor 30 is provided inside the chamber 10, and the
susceptor 30 supports a plurality of substrates W loaded from the
external. The susceptor 30 corresponds to an opposite electrode in
opposite to the plasma electrode 20, and the susceptor 30 is
electrically grounded by an elevating axis 32 for elevating the
susceptor 30.
[0016] The elevating axis 32 is moved up and down by an elevating
apparatus (not shown). In this case, the elevating axis 32 is
surrounded by a bellows 34 for sealing the elevating axis 32 and
the bottom surface of the chamber 10.
[0017] The gas distributing means 40 is provided below the plasma
electrode 20, wherein the gas distributing means 40 confronts with
the susceptor 30. In this case, a gas diffusion space 42 is formed
between the gas distributing means 40 and the plasma electrode 20.
Inside the gas diffusion space 42, the source gas supplied from the
gas supply pipe 26 penetrating through the plasma electrode 20 is
diffused. The gas distributing means 40 uniformly distributes the
source gas to the entire area of the reaction space through a
plurality of gas distributing holes 44 being communicated with the
gas diffusion space 42.
[0018] In case of the substrate processing apparatus according to
the related art, after the substrate (W) is loaded onto the
susceptor 30, the predetermined source gas is distributed to the
reaction space of the chamber 10, and the RF power is supplied to
the plasma electrode 20 so as to form the plasma in the reaction
space between the susceptor 30 and the gas distributing means 40,
to thereby deposit a source material of the source gas on the
substrate (W) by the use of plasma.
[0019] However, the substrate processing apparatus according to the
related art may have the following problems.
[0020] First, a density of the plasma formed on the entire area of
the susceptor 30 is not uniform so that a uniformity of the thin
film material deposited on the substrate (W) is deteriorated, and
it is difficult to control quality of the thin film.
[0021] Also, since the plasma is formed on the entire area of the
susceptor 30, a thickness of the source material deposited on the
chamber 10 as well as a thickness of the source material deposited
on the substrate (W) may be rapidly increased so that a cleaning
cycle of the chamber 10 is shortened.
SUMMARY
[0022] Accordingly, the present invention is directed to an
apparatus and method of processing substrate that substantially
obviates one or more problems due to limitations and disadvantages
of the related art.
[0023] An aspect of the present invention is to provide an
apparatus and method of processing substrate, which facilitates to
improve deposition uniformity of a thin film deposited on a
substrate, and to control quality of a thin film.
[0024] Another aspect of the present invention is to provide an
apparatus and method of processing substrate, which overcomes a
problem of particles by minimizing an accumulation thickness of
particles deposited on a process chamber.
[0025] Additional advantages and features of the invention will be
set forth in part in the description which follows and in part will
become apparent to those having ordinary skill in the art upon
examination of the following or may be learned from practice of the
invention. The objectives and other advantages of the invention may
be realized and attained by the structure particularly pointed out
in the written description and claims hereof as well as the
appended drawings.
[0026] To achieve these and other advantages and in accordance with
the purpose of the invention, as embodied and broadly described
herein, there is provided a substrate processing apparatus
comprising a process chamber; a substrate supporter for supporting
at least one of substrates, wherein the substrate supporter is
provided in the bottom of the process chamber; a chamber lid
confronting the substrate supporter, the chamber lid for covering
an upper side of the process chamber; and a gas distributor for
locally distributing activated source gas on the substrate, wherein
the gas distributor locally confronting the substrate supporter is
provided in the chamber lid, wherein the gas distributor forms
plasma by the use of plasma formation gas, and activates the source
gas by distributing the source gas to some of plasma area for
formation of the plasma.
[0027] In another aspect of the present invention, there is
provided a substrate processing apparatus comprising a process
chamber; a substrate supporter for supporting at least one of
substrates, wherein the substrate supporter is provided in the
bottom of the process chamber; a chamber lid confronting the
substrate supporter, the chamber lid for covering an upper side of
the process chamber; and a gas distributor for locally distributing
activated source gas on the substrate, wherein the gas distributor
locally confronting the substrate supporter is provided in the
chamber lid, and is formed to include a plasma formation space
prepared between a plasma electrode and a ground electrode, and a
source gas distribution space spatially separated from the plasma
formation space, wherein the gas distributor distributes source gas
to some of plasma area formed to include a lower area of the source
gas distribution space through the source gas distribution space,
and thus activates the source gas.
[0028] In another aspect of the present invention, there is
provided a substrate processing apparatus comprising a process
chamber; a substrate supporter for supporting at least one of
substrates, wherein the substrate supporter is provided in the
bottom of the process chamber; a chamber lid confronting the
substrate supporter, the chamber lid for covering an upper side of
the process chamber; and a gas distributor for locally distributing
activated source gas on the substrate, wherein the gas distributor
locally confronting the substrate supporter is provided in the
chamber lid, wherein the gas distributor forms plasma between
plasma and ground electrodes arranged in parallel, and distributes
source gas to a plasma overlapping area for formation of the
plasma, and thus activates the source gas.
[0029] In another aspect of the present invention, there is
provided a substrate processing method comprising placing at least
one substrate on a substrate supporter provided inside a process
chamber; and locally distributing activated source gas on the
substrate by the use of gas distributor which locally confronts the
substrate supporter and is provided in a chamber lid for covering
the process chamber, wherein the gas distributor forms plasma by
the use of plasma formation gas, and distributes source gas to a
plasma overlapping area for formation of the plasma, and thus
activates the source gas.
[0030] In a further aspect of the present invention, there is
provided a substrate processing method comprising placing at least
one substrate on a substrate supporter provided inside a process
chamber; and locally distributing activated source gas on the
substrate by the use of gas distributor which locally confronts the
substrate supporter and is provided in a chamber lid for covering
the process chamber, wherein the step of locally distributing the
activated source gas on the substrate includes forming plasma
between plasma and ground electrodes arranged in parallel, and
distributing source gas to a plasma overlapping area for formation
of the plasma, and thus activating the source gas.
[0031] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0033] FIG. 1 illustrates a substrate processing apparatus
according to the related art;
[0034] FIG. 2 is a perspective view illustrating a substrate
processing apparatus according to the embodiment of the present
invention;
[0035] FIG. 3 is a rear perspective view illustrating a gas
distribution module shown in FIG. 2;
[0036] FIG. 4 is a cross sectional view along II-II' of FIG. 3;
[0037] FIG. 5 illustrates a substrate processing method using the
substrate processing apparatus according to the embodiment of the
present invention;
[0038] FIG. 6 is a cross sectional view along I-I' of FIG. 2, which
shows a first modified embodiment of a gas distribution module;
[0039] FIG. 7 is a cross sectional view along I-I' of FIG. 2, which
shows a second modified embodiment of a gas distribution module;
and
[0040] FIG. 8 is a cross sectional view along I-I' of FIG. 2, which
shows a third modified embodiment of a gas distribution module.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Hereinafter, embodiments of the present invention will be
described in detail with reference to the accompanying
drawings.
[0042] FIG. 2 is a perspective view illustrating a substrate
processing apparatus according to the embodiment of the present
invention.
[0043] Referring to FIG. 2, the substrate processing apparatus
according to the embodiment of the present invention may include a
process chamber 110; a substrate supporter 120 provided on the
bottom of the process chamber 110, wherein the substrate supporter
120 supports at least one substrate (W) thereon; a chamber lid 130
for covering an upper side of the process chamber 110; and a gas
distributor 140 for distributing activated source gas on the
substrate (W), wherein the gas distributor 140 locally confronting
the chamber lid 130 is provided in the chamber lid 130.
[0044] The process chamber 110 provides a reaction space for
substrate processing, for example, a thin film deposition process.
A bottom surface and/or a lateral surface of the process chamber
110 may be communicated with an exhaust port (not shown) for
discharging gas from the reaction space.
[0045] The substrate supporter 120 is rotatably provided in the
inner bottom of the process chamber 110. The substrate supporter
120 is supported by a rotation axis (not shown) penetrating through
a central portion of the bottom surface of the process chamber 110,
and the substrate supporter 120 may be electrically floating or
grounded. In this case, the rotation axis exposed out of the bottom
surface of the process chamber 100 is sealed by a bellows (not
shown) provided in the bottom surface of the process chamber
110.
[0046] The substrate supporter 120 supports at least one substrate
(W) loaded by an external substrate loading apparatus (not shown).
The substrate supporter 120 may be formed in shape of a circular
plate. The substrate (W) may be a semiconductor substrate or a
wafer. In this case, it is preferable that the plurality of
substrates (W) be arranged at fixed intervals in a circular pattern
on the substrate supporter 120 so as to improve the yield.
[0047] According as the substrate supporter 120 is rotated to a
predetermined direction (for example, clockwise direction) by
rotation of the rotation axis, the substrate (W) is rotated and
thus is moved in accordance with a predetermined order so that the
substrate (W) is sequentially exposed to the activated source gas
which is locally distributed from the gas distributor 140.
Accordingly, the substrate (W) is sequentially exposed to the
activated source gas in accordance with rotation of the substrate
supporter 120 and its rotation speed, whereby a single-layered or
multi-layered thin film is deposited on the substrate (W) by ALD
(Atomic Layer Deposition) or CVD (Chemical Vapor Deposition).
[0048] The chamber lid 130 is provided on the process chamber 110,
that is, the chamber lid 130 covers the upper side of the process
chamber 110. The chamber lid 130 supports the gas distributor 140,
wherein the chamber lid 130 includes a plurality of module
receivers 130a, 130b, 130c and 130d provided at fixed intervals,
for example, a radial pattern, and each part of the gas distributor
140 is inserted into each of the module receivers 130a, 130b, 130c
and 130d. The plurality of module receivers 130a, 130b, 130c and
130d may be symmetrically provided in a diagonal direction with
respect to a central point of the chamber lid 130, that is, may be
disposed every 90.degree..
[0049] As shown in the drawings, the process chamber 110 and the
chamber lid 130 may be formed in the circular shape, but not
limited to the circular shape. For example, the process chamber 110
and the chamber lid 130 may be formed in a polygonal shape such as
hexagon, or an oval shape. If the process chamber 110 and the
chamber lid 130 are formed in the polygonal shape such as hexagon,
the process chamber 110 is provided in such a way that a plurality
of sections obtained by dividing the process chamber 110 are
combined with one another.
[0050] In FIG. 2, the chamber lid 130 includes the four module
receivers 130a, 130b, 130c and 130d, but not limited to the four.
For example, the chamber lid 130 may include 2N (`N` is an integer
above 0) module receivers symmetrically provided with respect to
the central point of the chamber lid 130. In this case, the
plurality of module receivers may be mutually symmetric in the
diagonal direction with respect to the central point of the chamber
lid 130. Hereinafter, it is assumed that the chamber lid 130
includes the first to fourth module receivers 130a, 130b, 130c and
130d.
[0051] The gas distributor 140 locally confronting the substrate
supporter 120 is provided in the chamber lid 130, wherein the gas
distributor 140 distributes the activated source gas on the
substrate (W). That is, the gas distributor 140 forms plasma by the
use of plasma formation gas, and distributes the source gas to some
of plasma area with the plasma, to thereby activate the source gas.
Accordingly, the source gas distributed from the gas distributor
140 is activated by the plasma formed in some of the plasma area,
and the activated source gas is distributed on the substrate (W),
whereby a predetermined thin film is formed on the upper surface of
the substrate (W).
[0052] The gas distributor 140 includes first to fourth gas
distribution modules 140a, 140b, 140c and 140d which are
respectively inserted into the first to fourth module receivers
130a, 130b, 130c and 130d while locally confronting different areas
of the substrate supporter 120.
[0053] FIG. 3 is a rear perspective view illustrating a gas
distribution module shown in FIG. 2. FIG. 4 is a cross sectional
view along II-If of FIG. 3.
[0054] Referring to FIGS. 3 and 4 in connection with FIG. 2, each
of the first to fourth gas distribution modules 140a, 140b, 140c
and 140d may include a housing 141, first and second plasma
electrodes 143a and 143b, and first and second insulating members
145a and 145b.
[0055] The housing 141 may include a ground plate 141a placed onto
the upper surface of the chamber lid 130, and a plurality of ground
electrodes 141b protruding from the lower surface of the ground
plate 141a, wherein the plurality of ground electrodes 141b having
a predetermined height form a first plasma formation space (S1), a
second plasma formation space (S2), and a source gas distribution
space (S3) which are spatially separated from one another.
[0056] The ground plate 141a is placed onto the upper surface of
the chamber lid 130, and is connected with the upper surface of the
chamber lid 130 by a plurality of coupling members (not shown) such
as blot or screw, whereby the ground plate 141a is electrically
grounded through the chamber lid 130.
[0057] The plurality of ground electrodes 141b may include four
ground sidewalls 141b1 protruding from the lower edge of the ground
plate 141a; and first and second ground partitions 141b2 and 141b3
provided to spatially separate the space prepared by the four
ground sidewalls 141b1 into the first plasma formation space (S1),
the second plasma formation spaces (S2), and the source gas
distribution space (S3).
[0058] The first plasma formation space (S1) is prepared between
the ground sidewall 141b1 and the first ground partition 141b2, and
the second plasma formation space (S2) is prepared between the
ground sidewall 141b1 and the second ground partition 141b3. Each
of the first and second plasma formation spaces (S1, S2) is formed
in a polygonal shape whose length is larger than a length of the
substrate (W). Each of the first and second plasma formation spaces
(S1, S2) is communicated with a plurality of first gas supplying
holes formed in the upper surface of the housing 141, that is, the
ground plate 141a, and is also supplied with plasma formation gas
(G1) from a first gas supplier (not shown) through a first gas
supplying pipe (not shown) connected with the plurality of first
gas supplying holes. The plasma formation gas (G1) may be inert gas
such as argon (Ar) or nitrogen (N2), reactant gas such as hydrogen
(H2), nitrogen (N2), oxygen (O2), nitrogen dioxide (N2O) and ozone
(O3), or mixed gas of the inert gas and the reactant gas.
[0059] The source gas distribution space (S3) is prepared between
the first and second ground partitions 141b2 and 141b3, to thereby
spatially separate the first and second plasma formation spaces
(S1, S2) from each other. The source gas distribution space (S3) is
communicated with a plurality of second gas supplying holes formed
in the upper surface of the housing 141, that is, the ground plate
141a, and is also supplied with source gas (G2) from a second gas
supplier (not shown) through a second gas supplying pipe (not
shown) connected with the plurality of second gas supplying holes.
The source gas (G2) may include a thin film material to be
deposited on the substrate (W). The source gas (G2) may include the
thin film material of silicon (Si), titanium family element (Ti,
Zr, Hf, and etc.), or aluminum (Al). For example, the source gas
(G2) including the thin film material of silicon (Si) may be the
gas selected from silane (SiH4), disilane (Si2H6), trisilane
(Si3H8), TEOS (Tetraethylorthosilicate), DCS (Dichlorosilane), HCD
(Hexachlorosilane), TriDMAS (Tri-dimethylaminosilane), TSA
(Trisilylamine), and etc.
[0060] The source gas (G2) may be mixed with the reactant gas such
as hydrogen (H2), nitrogen (N2), oxygen (O2), nitrogen dioxide
(N2O) and ozone (O3).
[0061] In FIG. 3, the source gas distribution space (S3) is
provided in a type of slit, but not limited to this shape. For
example, the lower surface of the source gas distribution space
(S3) may include a plurality of source gas distribution holes (not
shown). That is, the lower surface of the source gas distribution
space (S3) may be provided with a shower head having a plurality of
source gas distribution holes.
[0062] The first plasma electrode 143a is inserted into the first
plasma formation space (S1) while being electrically insulated from
the housing 141, and is also arranged in parallel to the first
ground partition 141b2. In this case, a distance (d1) between the
first plasma electrode 143a and the first ground partition 141b2 or
a distance (d1) between the first plasma electrode 143a and the
ground sidewall 141b1 is smaller than a height (H1) between the
first plasma electrode 143a and the substrate (W). In this case,
since an electric field is not formed between the substrate (W) and
the first plasma electrode 143a, it is possible to prevent the
substrate (W) from being damaged by the plasma formed by the use of
electric field.
[0063] The first plasma electrode 143a is electrically connected
with a first plasma power supplier 147a, and is supplied with a
first plasma power from the first plasma power supplier 147a. In
this case, a first feed member (not shown) for electrically
connecting the first plasma electrode 143a with the first plasma
power supplier 147a may be connected with an impedance matching
circuit (not shown). The impedance matching circuit matches source
impedance and load impedance of the first plasma power supplied to
the first plasma electrode 143a from the first plasma power
supplier 147a. The impedance matching circuit may include at least
two of impedance element (not shown) formed of at least one of
variable capacitor and variable inductor.
[0064] The first plasma power may be high frequency power or radio
frequency (RF) power, for example, lower frequency (LF) power,
middle frequency (MF) power, high frequency (HF) power, or very
high frequency (VHF) power. In this case, the LF power may have 3
kHz.about.300 kHz frequency, the MF power may have 300 kHz.about.3
MHz frequency, the HF power may have 3 MHz.about.30 MHz frequency,
and the VHF power may have 30 MHz.about.300 MHz frequency.
[0065] The first plasma electrode 143a forms first plasma by the
use of plasma formation gas (G1) supplied in the first plasma
formation space (S1) according to the first plasma power. In this
case, a first plasma area (PA1) for forming the first plasma
includes an area positioned adjacent to a lower end of the first
plasma electrode 143a and a lower end of the ground electrode 141b,
and some of a lower area of the source gas distribution space (S3)
by the electric field formed between the first plasma electrode
143a and the ground electrode 141b. That is, if the distance (d1)
between the first plasma electrode 143a and the ground electrode
141b is not more than a predetermined distance, the plasma is not
formed in the space between the first plasma electrode 143a and the
ground electrode 141b. If the distance (d1) between the first
plasma electrode 143a and the ground electrode 141b is small, and
the plasma formation gas (G1) is distributed to the space between
the first plasma electrode 143a and the ground electrode 141b, the
plasma is formed in the area positioned adjacent to the lower end
of the first plasma electrode 143a and the lower end of the ground
electrode 141b, and some of the lower area of the source gas
distribution space (S3). According as the source gas (G2) is
distributed from the source gas distribution space (S3), the source
gas (G2) is limitedly activated (or activated at minimum), whereby
it is possible to minimize a deposition of the activated source gas
on a portion adjacent to the electrode. Also, some of the source
gas (G2) is activated and distributed on the substrate (W), whereby
it is possible to improve a deposition efficiency in comparison to
a process of depositing the source gas (G2) without activation.
[0066] The second plasma electrode 143b is inserted into the second
plasma formation space (S2) while being electrically insulated from
the housing 141, and is also arranged in parallel to the second
ground partition 141b3. In this case, a distance (d1) between the
second plasma electrode 143b and the second ground partition 141b3
or a distance (d1) between the second plasma electrode 143b and the
ground sidewall 141b1 is smaller than a height (H1) between the
second plasma electrode 143b and the substrate (W). In this case,
since an electric field is not formed between the substrate (W) and
the second plasma electrode 143b, it is possible to prevent the
substrate (W) from being damaged by the plasma formed by the use of
electric field.
[0067] The second plasma electrode 143b is electrically connected
with a second plasma power supplier 147b, and is supplied with a
second plasma power from the second plasma power supplier 147b. In
this case, a second feed member (not shown) for electrically
connecting the second plasma electrode 143b with the second plasma
power supplier 147b may be connected with the aforementioned
impedance matching circuit (not shown).
[0068] The second plasma power may be high frequency power or radio
frequency (RF) power which is the same as or different from the
first plasma power. If the second plasma power is the same as the
first plasma power, both the first plasma power and the second
plasma power may be supplied by the use of one plasma power
supplier.
[0069] The second plasma electrode 143b forms second plasma by the
use of plasma formation gas (G1) supplied in the second plasma
formation space (S2) according to the second plasma power. In this
case, a second plasma area (PA2) for forming the second plasma
includes an area positioned adjacent to a lower end of the second
plasma electrode 143b and a lower end of the ground electrode 141b,
and some of a lower area of the source gas distribution space (S3)
by the electric field formed between the second plasma electrode
143b and the ground electrode 141b, in the same manner as the
aforementioned first plasma.
[0070] The source gas distribution space (S3) may be partially
overlapped with the first plasma area (PA1) and/or the second
plasma area (PA2), or may be overlapped with an overlapping area of
the first and second plasma areas (PA1, PA2). Thus, according as
the source gas (G2) supplied to the source gas distribution space
(S3) is distributed to the first plasma area (PA1) and/or the
second plasma area (PA2), or the overlapping area of the first and
second plasma areas (PA1, PA2), the source gas (G2) is activated by
the plasma of the first and second plasma areas (PA1, PA2), whereby
the activated source gas (AG2) is distributed on the substrate
(W).
[0071] The first insulating member 145a is inserted into a first
insulating member insertion hole formed in the housing 141, whereby
the first plasma electrode 143a is electrically insulated from the
housing 141. The first insulating member 145a includes an electrode
insertion hole into which the first plasma electrode 143a is
inserted.
[0072] The second insulating member 145b is inserted into a second
insulating member insertion hole formed in the housing 141, whereby
the second plasma electrode 143b is electrically insulated from the
housing 141. The second insulating member 145b includes an
electrode insertion hole into which the second plasma electrode
143b is inserted.
[0073] FIG. 5 illustrates a substrate processing method using the
substrate processing apparatus according to the embodiment of the
present invention.
[0074] The substrate processing method using the substrate
processing apparatus according to the embodiment of the present
invention will be described with reference to FIG. 5 in connection
with FIG. 4.
[0075] First, the plurality of substrates (W) are loaded at fixed
intervals and placed onto the substrate supporter 120.
[0076] Then, the substrate supporter 120 having the plurality of
substrates (W) loaded and placed thereonto is rotated to the
predetermined direction (for example, clockwise direction).
[0077] According as the plasma power and the plasma formation gas
(G1) are supplied to the respective first to fourth gas
distribution modules 140a, 140b, 140c and 140d, the plasma is
formed inside each of the first to fourth gas distribution modules
140a, 140b, 140c and 140d, and the source gas (G2) is distributed
to some area of the plasma, whereby the source gas (G2) is
activated, and the activated source gas (AG2) is downwardly
distributed and locally provided on the substrate supporter
120.
[0078] In more detail, the plasma formation gas (G1) is supplied to
the first and second plasma formation spaces (S1, S2) in each of
the first to fourth gas distribution modules 140a, 140b, 140c and
140d; and the plasma power is supplied to the first and second
plasma electrodes 143a and 143b in each of the first to fourth gas
distribution modules 140a, 140b, 140c and 140d, whereby the plasma
is formed in the lower area of the first and second plasma
formation spaces (S1, S2) and the lower area of the source gas
distribution space (S3). Subsequently, according as the source gas
(G2) is supplied to the source gas distribution space (S3) of each
of the first to fourth gas distribution modules 140a, 140b, 140c
and 140d, the source gas (G2) is distributed to the plasma formed
in the lower area of the source gas distribution space (S3). Thus,
the source gas (G2) is activated by the plasma while the source gas
(G2) passes through the plasma formed in the lower area of the
source gas distribution space (S3), and the activated source gas
(AG2) is distributed on the substrate (W) by the flux of the source
gas (G2) supplied to the source gas distribution space (S3).
[0079] Accordingly, each of the plurality of substrates (W) placed
onto the substrate supporter 120 sequentially passes through the
respective lower areas of the first to fourth gas distribution
modules 140a, 140b, 140c and 140d by rotation of the substrate
supporter 120, whereby each of the substrates (W) is exposed to the
activated source gas (AG2), and thus a predetermined thin film is
deposited on each of the substrates (W) by the activated source gas
(AG2).
[0080] FIG. 6 is a cross sectional view along I-I' of FIG. 2, which
shows a first modified embodiment of a gas distribution module.
[0081] Referring to FIG. 6 in connection with FIG. 2, each of gas
distribution modules 140a, 140b, 140c and 140d according to the
first modified embodiment of the present invention may include a
housing 141, first and second plasma electrodes 143a and 143b, and
first and second insulating members 145a and 145b.
[0082] The housing 141 may include a ground plate 141a placed onto
an upper surface of a chamber lid 130, and a plurality of ground
electrodes 141b protruding from a lower surface of the ground plate
141a, wherein the plurality of ground electrodes 141b having a
predetermined height form first and second plasma formation spaces
(S1, S2) which are spatially separated from each other.
[0083] The ground plate 141a is placed onto the upper surface of
the chamber lid 130, and is connected with the upper surface of the
chamber lid 130 by a plurality of coupling members (not shown) such
as blot or screw, whereby the ground plate 141a is electrically
grounded through the chamber lid 130.
[0084] The plurality of ground electrodes 141b may include four
ground sidewalls 141b1 protruding from the lower edge of the ground
plate 141a; and a ground partition 141b1 for dividing a space
prepared by the four ground sidewalls 141b1 so as to form the first
and second plasma formation spaces (S1, S2) spatially separated
from each other, and also to form a source gas distribution space
(S3) thereinside.
[0085] The first plasma formation space (S1) is prepared at one
side of the ground sidewall 141b1 and the ground partition 141b2,
and the second plasma formation space (S2) is prepared at the other
side of the ground sidewall 141b1 and the ground partition 141b2.
Each of the first and second plasma formation spaces (S1, S2) is
communicated with a plurality of first gas supplying holes formed
in the upper surface of the housing 141, that is, the ground plate
141a, and is supplied with the aforementioned plasma formation gas
(G1) from a first gas supplier (not shown) through a first gas
supplying pipe (not shown) connected with the plurality of first
gas supplying holes.
[0086] The source gas distribution space (S3) is prepared inside
the ground partition 141b2 so as to spatially separate the first
and second plasma formation spaces (S1, S2) from each other. The
source gas distribution space (S3) is communicated with a plurality
of second gas supplying holes formed in the upper surface of the
housing 141, that is, the ground plate 141a, and is supplied with
the aforementioned source gas (G2) from a second gas supplier (not
shown) through a second gas supplying pipe (not shown) connected
with the plurality of second gas supplying holes.
[0087] In FIG. 6, the source gas distribution space (S3) is
provided in a type of slit, but not limited to this shape. For
example, the lower surface of the source gas distribution space
(S3) may include a plurality of source gas distribution holes (not
shown).
[0088] The first and second plasma electrodes 143a and 143b are
respectively inserted into the first and second plasma formation
spaces (S1, S2), which are the same as those of the FIG. 4, whereby
a detailed explanation for the same structures will be omitted.
[0089] The first plasma electrode 143a forms first plasma by the
use of plasma formation gas (G1) supplied to the first plasma
formation space (S1) according to first plasma power. Accordingly,
a first plasma area (PA1) for forming the first plasma includes an
area positioned adjacent to a lower end of the first plasma
electrode 143a and a lower end of the ground electrode 141b, and
some of a lower area of the source gas distribution space (S3),
that is, some of a lower area of the ground partition 141b2 by an
electric field formed between the first plasma electrode 143a and
the ground electrode 141b according to the first plasma power.
[0090] In the same manner, the second plasma electrode 143b forms
second plasma by the use of plasma formation gas (G1) supplied to
the second plasma formation space (S2) according to second plasma
power. Accordingly, a second plasma area (PA2) for forming the
second plasma includes an area positioned adjacent to a lower end
of the second plasma electrode 143b and a lower end of the ground
electrode 141b, and some of a lower area of the source gas
distribution space (S3), that is, some of a lower area of the
ground partition 141b2 by an electric field formed between the
second plasma electrode 143b and the ground electrode 141b
according to the second plasma power.
[0091] The source gas distribution space (S3) may be partially
overlapped with the first plasma area (PA1) and/or the second
plasma area (PA2), or may be overlapped with an overlapping area of
the first and second plasma areas (PA1, PA2). Thus, according as
the source gas (G2) supplied to the source gas distribution space
(S3) is distributed to the first plasma area (PA1) and/or the
second plasma area (PA2), or the overlapping area of the first and
second plasma areas (PA1, PA2), the source gas (G2) is activated by
the plasma of the first and second plasma areas (PA1, PA2), whereby
the activated source gas (AG2) is distributed on the substrate
(W).
[0092] FIG. 7 is a cross sectional view along I-I' of FIG. 2, which
shows a second modified embodiment of a gas distribution
module.
[0093] Referring to FIG. 7 in connection with FIG. 2, each of gas
distribution modules 140a, 140b, 140c and 140d according to the
second modified embodiment of the present invention may include a
housing 141, first and second plasma electrodes 143a and 143b, and
first and second insulating members 145a and 145b. Except that each
of the first and second plasma electrodes 143a and 143b is not
protruding out of a lower surface of a ground electrode 141b, that
is, a lower surface of a housing 141, each of the gas distribution
modules according to the second modified embodiment of the present
invention is identical in structure to that of the gas distribution
modules according to the first modified embodiment of the present
invention shown in FIG. 6.
[0094] In more detail, a height (H2) between the first plasma
electrode 143a and the substrate (W) is larger than a height (H1)
between the substrate (W) and a ground partition 141b2 for
formation of a source gas distribution space (S3). Also, a height
(H2) between the second plasma electrode 143b and the substrate (W)
is larger than the height (H1) between the substrate (W) and the
ground partition 141b2 for formation of the source gas distribution
space (S3). Also, a distance (d2) between the first plasma
electrode 143a and the ground electrode 141b is smaller than the
height (H1) between the substrate (W) and the ground partition
141b2 provided with the source gas distribution space (S3). In this
case, the distance (d2) between the first plasma electrode 143a and
the ground electrode 141b is relatively smaller than the
aforementioned distance (d1) of FIG. 4. In the same manner, the
distance (d2) between the second plasma electrode 143b and the
ground electrode 141b is relatively smaller than the aforementioned
distance (d1) of FIG. 4.
[0095] When the plasma formation gas (G1) is supplied to the first
and second plasma formation spaces (S1, S2) in each of the gas
distribution modules 140a, 140b, 140c and 140d according to the
second modified embodiment of the present invention, and the plasma
power is applied to the first and second plasma electrodes 143a and
143b, the plasma is formed between the lower area of the plasma
electrodes 143a and 143b and the lower area of the ground electrode
141b. In this case, first and second plasma areas (PA1, PA2) for
formation of the plasma may be overlapped with each other in the
lower area of the ground partition 141b2 provided with the source
gas distribution space (S3) by an electric field. According as the
source gas (G2) distributed from the source gas distribution space
(S3) is distributed to the overlapping area of the first and second
plasma areas (PA1, PA2) in the lower area of the ground partition
141b2, the source gas (G2) is activated by the plasma in the
overlapping area of the first and second plasma areas (PA1, PA2),
and then the activated source gas (AG2) is distributed on the
substrate (W).
[0096] FIG. 8 is a cross sectional view along I-I' of FIG. 2, which
shows a third modified embodiment of a gas distribution module.
[0097] Referring to FIG. 8 in connection with FIG. 2, each of gas
distribution modules 140a, 140b, 140c and 140d according to the
third modified embodiment of the present invention may include a
housing 141, first and second plasma electrodes 143a and 143b, and
first and second insulating members 145a and 145b. Except that a
reactant gas distribution space (S4) is additionally formed inside
each of the first and second plasma electrodes 143a and 143b, each
of the gas distribution modules according to the third modified
embodiment of the present invention is identical in structure to
that of the gas distribution modules according to the first
modified embodiment of the present invention shown in FIG. 6.
[0098] In more detail, the reactant gas distribution space (S4) is
formed inside each of the first and second plasma electrodes 143a
and 143b, wherein the reactant gas distribution space (S4) is
supplied with the aforementioned reactant gas (G3) from a third gas
supplier (not shown). In FIG. 8, the reactant gas distribution
space (S4) is formed in type of a slit, but not limited to this
shape. For example, a lower surface of the reactant gas
distribution space (S4) may include a plurality of source gas
distribution holes (not shown).
[0099] When plasma formation gas (G1) is supplied to first and
second plasma formation spaces (S1, S2) in each of the gas
distribution modules 140a, 140b, 140c and 140d according to the
third modified embodiment of the present invention, and plasma
power is applied to the first and second plasma electrodes 143a and
143b, plasma is formed in the first and second plasma formation
spaces (S1, S2), lower areas of the plasma electrodes 143a and
143b, and a lower area of a ground electrode 141b. In this case,
each of first and second plasma areas (PA1, PA2) for formation of
the plasma may include a lower area of a ground partition 141b2
provided with a source gas distribution space (S3) by an electric
field, and a lower area of each of the first and second plasma
electrodes 143a and 143b provided with the reactant gas
distribution space (S4). According as source gas (G2) distributed
from the source gas distribution space (S3) is distributed to an
overlapping area of the first and second plasma areas (PA1, PA2),
the source gas (G2) is activated by the plasma in the overlapping
area of the first and second plasma areas (PA1, PA2), and then the
activated source gas (AG2) is distributed on the substrate (W).
Also, according as the reactant gas (G3) distributed from the
reactant gas distribution space (S4) is distributed to each of the
first and second plasma areas (PA1, PA2) formed in the lower area
of each plasma electrode 143a and 143b, the reactant gas (G3) is
activated by the plasma of each of the first and second plasma
areas (PA1, PA2), and then the activated reactant gas (AG3) is
distributed on the substrate (W).
[0100] In each of the gas distribution modules 140a, 140b, 140c and
140d according to the third modified embodiment of the present
invention, each of the plasma electrodes 143a and 143b and the
ground electrode 141b is provided at the same height (H1) from the
substrate (W), but not limited to this structure. For example, as
shown in the gas distribution module according to the
aforementioned second modified embodiment of FIG. 7, any one of the
plasma electrodes 143a and 143b and the ground electrode 141b may
be more adjacent to the substrate (W). In this case, it is
preferable that the source gas (G2) be distributed from the gas
distribution space (S3, S4) formed inside the plasma electrode 143a
and 143b or the ground electrode 141b, which is positioned more
adjacent to the substrate (W). For example, if the ground electrode
141b is positioned more adjacent to the substrate (W) in comparison
to the plasma electrode 143a and 143b, the source gas (G2) is
distributed from the gas distribution space (S3) formed inside the
ground electrode 141b, and the reactant gas (G3) is distributed
from the gas distribution space (S4) formed inside the plasma
electrode 143a and 143b. Meanwhile, if the plasma electrode 143a
and 143b is positioned more adjacent to the substrate (W) in
comparison to the ground electrode 141b, the reactant gas (G3) is
distributed from the gas distribution space (S3) formed inside the
ground electrode 141b, and the source gas (G2) is distributed from
the gas distribution space (S4) formed inside the plasma electrode
143a and 143b.
[0101] As shown above, the substrate processing apparatus and
method according to the embodiment of the present invention enables
to form the plasma in each of the first and second plasma formation
spaces (S1, S2) spatially separated from each other, to activate
the source gas (G2) by distributing the source gas (G2) to some of
the plasma area through the use of source gas distribution space
(S3) partially overlapped with some of the plasma area for
formation of the plasma, and to distribute the activated source gas
(AG2) on the substrate (W), thereby improving deposition uniformity
of thin film deposited on the substrate (W), facilitating quality
control of thin film, and minimizing particles by realizing a
minimum accumulation thickness of particles deposited on a process
chamber.
[0102] Also, the substrate processing apparatus and method
according to the embodiment of the present invention enables to
form the plasma in each of the first and second plasma formation
spaces (S1, S2) spatially separated from each other, to activate
the source gas (G2) and reactant gas (G3) by distributing the
source gas (G2) and reactant gas (G3) to some of the plasma area
through the use of source gas distribution space (S3) and reactant
gas distribution space (S4) partially overlapped with some of the
plasma area for formation of the plasma, and to distribute the
activated source gas (AG2) and reactant gas (AG3) on the substrate
(W), thereby improving deposition uniformity of thin film deposited
on the substrate (W), facilitating quality control of thin film,
and minimizing particles by realizing a minimum accumulation
thickness of particles deposited on a process chamber.
[0103] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the inventions. Thus,
it is intended that the present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *